1. Field of the Invention
The present invention relates generally to devices for the removal and straining of suspended substances from fluids and, more particularly, to a fluid filtering and straining device for use with a fluid circulation system. Specifically, the present invention relates to a strainer and filtration assembly for use in filtering debris and other suspended substances from the water of a swimming pool or water fountain recirculation system.
2. Description of the Prior Art
There are numerous different types of fluid circulation systems used in a wide variety of applications including air or hydraulic fluid systems, swimming pool and water fountain recirculation systems, water irrigation delivery systems, and the like. All of these fluid circulation systems have several common elements. Such fluid circulation systems include some type of fluid reservoir or source and require that fluid be moved from the reservoir to an ultimate destination, which may include a return to the reservoir. Such fluid movement is generally accomplished using a vacuum pump system, and it is generally desirable and often required that the fluid from the reservoir first be filtered and/or strained before it is allowed to enter the vacuum pump to prevent clogging and damage to the pumping system. The fluid may be liquid, gel or gas.
U.S. Pat. No. 4,387,022 illustrates a filtering device for use in a hydraulic fluid system, while U.S. Pat. Nos. 4,045,351, 6,106,709 and U.S. Pat. No. 6,210,573 all disclose water filtration devices for a variety of different applications including, respectively, a bathroom or kitchen sink, an aquarium, and a washing machine. None of these devices are adapted to handle large volumes of fluid and the problems inherent with filtering and straining debris therefrom.
U.S. Pat. Nos. 4,430,214, 5,750,022, 5,888,386 and U.S. Pat. No. 6,080,324 all disclose filtration and strainer devices for use in removing debris from water recirculation systems in swimming pools. In particular, U.S. Pat. No. 4,430,214 discloses a device wherein the debris is shredded before entering the pump in order to promote ease of passage of the debris through the pump. The remaining three patents all disclose filtration devices wherein debris is captured by a porous net or plate in such a manner as to gradually restrict water flow therethrough due to the accumulation of debris on or in the filtering structure This accumulation of debris may cause a gradual change in the water pressure between the inlet and the outlet of the filtering device thereby increasing the workload of the vacuum pump over time. This situation can in turn cause a reduction in the filtration and recirculation efficiency for the swimming pool system and, if left uncorrected by removal of the debris from the filtering structure, may cause premature failure of the vacuum pump.
In addition to the above, many commercially available strainer pots for swimming pools or fountains have a high profile and limited capacity. As a result, they are dramatically oversized or are used in multiples of two which adds to both the cost as well as the maintenance of the overall system. Accordingly, there remains a need in the industry for a filtration and straining device which effectively filters debris from fluid of all types without substantial pressure changes within the device resulting from debris accumulation. Moreover, there remains a need for such a device which is compact in design, has a low profile and high-volume, is capable of in-line installation, and is easy to access for cleaning purposes.